* Oil, metals slip again on worries over Fed's direction * Dollar's strength weighs further on commodities * Soybeans hit 6-week bottom, cocoa 8-1/2 month lows * Mixed US jobs report comforts some, worries others By Barani Krishnan NEW YORK, Jan 4 (Reuters) - Oil and metals prices fell for a second straight day on Friday as investors weighed the possibility of the U.S. Federal Reserve ending its highly stimulative monetary policy and as data showed anemic jobs growth in the